Problem: A bag contains $11$ red jelly beans, $7$ green jelly beans, and $10$ blue jelly beans. If a jelly bean is randomly chosen, what is the probability that it is not green?
Explanation: There are $11 + 7 + 10 = 28$ jelly beans in the bag. There are $7$ green jelly beans. That means $28 - 7 = 21$ are not green. The probability is $ \frac{21}{28} = \dfrac{3}{4}$.